Path Loss in WBAN

Report
Ubiquitous Healthcare Using MAC
Protocols in Wireless Body Area
Sensor Networks (WBASNs)
Group Members
• Muhammad Sarim Hayat
FA08-BET-131
• Nadir Ali Khan
FA08-BET-089
• Umair Rafiq
FA08-BET-132
OUTLINE
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Abstract
Introduction
Summary of Architectures of WBANs
Energy Efficient MAC Protocols
MAC Frame structure
Path Loss in WBAN
Conclusion
OUTLINE
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•
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•
•
•
•
Abstract
Introduction
Summary of Architectures of WBANs
Energy Efficient MAC Protocols
MAC Frame structure
Path Loss in WBAN
Conclusion
Abstract(1/2)
• Wireless Body Area Sensor Networks (WBASNs)
• Ubiquitous Healthcare (UHC)
o Survey of different architectures of WBANs
o Functionality of devices used in architectures
• Survey of different MAC protocols used in
WBASNs
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Advantages and disadvantages is discussed
Trade-offs
Mechanisms used by different protocols
Analyses of different MAC protocols with respect to
different architectures used in UHC
Abstract(2/2)
• Path loss in WBAN
o In-body Communication
 With respect to MAC Protocols
With respect to WBAN models
o On-body Communication
With respect to MAC Protocols
With respect to distance, amplitude and RMS delay
o Off-body communication
With respect to MAC Protocols
OUTLINE
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•
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•
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Abstract
Introduction
Summary of Architectures of WBANs
Energy Efficient MAC Protocols
MAC Frame structure
Path Loss in WBAN
Conclusion
Introduction (1/3)
• WBASNs
o Emerging domain of wireless communication
o A lot of advancement in this domain
o Consists of tiny sensors
• UHC
o Provided to patients all around the globe, especially to
elderly peoples
o Different architectures are discussed
o Each architecture has its own applications depending upon
the communication scenarios
Introduction (2/3)
• Energy Efficiency of the system
o One of the basic requirement for WBASNs because of
limited power of batteries
o Life time of a node depends upon:
Energy consumption during communication
Energy wastage during communication
 Packet collision
 Overhearing
 Idle listening
 Over emitting
 Control overhead
Introduction (3/3)
• Path loss
o Data is transferred through wireless medium so path
loss is probable to occur
o Path loss is different for different scenarios and it
depends upon:
 Frequency of operations
Distance between transmitter and receiver nodes (d)
Most Frequently Used Standards for
WBAN Communication
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IEEE 802.15.1 Bluetooth
ZigBee
Medical Implant Communications Service (MICS)
IEEE 802.15.6 Ultra Wide Band (UWB)
Wearable Sensors used for Ubiquitous
HealthCare
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Wrist watch (eWatch)
Oximeter
Chest belt
Wearable shirt type (smart shirt/life shirt)
General WBAN Architecture
General WBAN Architecture
General WBAN Architecture
General WBAN Architecture
OUTLINE
•
•
•
•
•
•
•
Abstract
Introduction
Summary of Architectures of WBANs
Energy Efficient MAC Protocols
MAC Frame structure
Path Loss in WBAN
Conclusion
OUTLINE
•
•
•
•
•
•
•
Abstract
Introduction
Summary of Architectures of WBANs
Energy Efficient MAC Protocols
MAC Frame structure
Path Loss in WBAN
Conclusion
Energy Efficient MAC Protocols
• MAC Layer is the most suitable layer for
discussing energy and power issues
• Collision avoidance for energy efficiency,
minimum latency, high throughput, and
communication reliability, are basic requirements
in the design of MAC protocol.
• There are several sources of energy wastage:
Energy minimization techniques in
MAC Protocols for WBANs (1/2)
• There are three main approaches adopted for the
energy saving mechanisms in MAC protocols for
WBANs, which are listed and discussed below:
o Low Power Listening (LPL)
 Node awakes for a very short period to check activity of channel
 If the channel is not idle then the node remains in active state to
receive data and other nodes go back to sleeping mode.
 LPL is sensitive to traffic rates
Energy minimization techniques in
MAC Protocols for WBANs (2/2)
o Scheduled Contention
 Combination of the scheduling and contention based mechanisms
 In Contention based protocols, contending nodes try to access the
channel for data transmission
 Scheduling or Contention free means that each node has the
schedule of transmission in the form of bandwidth or time slot.
o Time Division Multiple Access (TDMA)
 Time slots are allocated to the sensor nodes by a master node
(MN).
 This scheme is highly sensitive to clock drift
 The scheme is power efficient because a node gets time slot for
transmission of data and remains in sleep mode for rest of the
time
Advantages and disadvantages of MAC Protocols
Advantages and disadvantages of MAC Protocols
Advantages and disadvantages of MAC Protocols
Advantages and disadvantages of MAC Protocols
Advantages and disadvantages of MAC Protocols
Advantages and disadvantages of MAC Protocols
Advantages and disadvantages of MAC Protocols
Advantages and disadvantages of MAC Protocols
Advantages and disadvantages of MAC Protocols
Energy minimization mechanism in
MAC protocols
Energy minimization mechanism in
MAC protocols
Energy minimization mechanism in
MAC protocols
Energy minimization mechanism in
MAC protocols
Energy minimization mechanism in
MAC protocols
Energy minimization mechanism in
MAC protocols
Energy minimization mechanism in
MAC protocols
Energy minimization mechanism in
MAC protocols
Performance Trade-offs made by MAC
Protocols
Observations
o For Static Topology in WBANs
Ta-MAC is best suited for Traffic System Architecture of
WBASNs used for UHC
It uses different mechanisms for on demand,
emergency and normal traffics
o For Dynamic Topology in WBANs
B-MAC is best suited for all other architectures of
WBASNs
OUTLINE
•
•
•
•
•
•
•
Abstract
Introduction
Summary of Architectures of WBANs
Energy Efficient MAC Protocols
MAC Frame structure
Path Loss in WBAN
Conclusion
MAC Frame structure(1/2)
• MAC frame structure consists of control portion or
control packet and data portion.
• Control portion is responsible for the management
and control messages
• Data portion consist of two sub parts:
o Contention Access Period (CAP)
o Contention Free Period (CFP)
MAC Frame structure(2/2)
Comparison Between IEEE 802.15.4
MAC and Original
Data Traffic Control
Data Traffic Control
Data Traffic Control
Data
DataTraffic
TrafficControl
Control
OUTLINE
•
•
•
•
•
•
•
Abstract
Introduction
Summary of Architectures of WBANs
Energy Efficient MAC Protocols
MAC Frame structure
Path Loss in WBAN
Conclusion
Path Loss in WBAN (1/2)
• WBASNs is greatly influenced by the amount of path
loss that occurs due to different impairments.
• Devices for WBASNs are generally placed inside or on
the body surface.
• Reduction in power density of an electromagnetic wave
introduces path loss.
Path Loss in WBAN (2/2)
• The path loss model in dB between the transmitting
and the receiving sensor nodes as a function of the
distance d is computed by as:
Scenarios of Path loss
• Three scenarios of Path loss:
 In-Body Communication
 On-Body Communication
 Off-Body Communication
Nodes to Calculate Path Loss in WBAN
• Implant node
• Body Surface node
• External node
Effect of WBASN Antennas
• Electrical antennas, such as dipole
• Magnetic antennas, such as loop
Characteristics of Human Body
• Not Ideal Medium for Communication
• Human body consists of materials with different
dielectric, thickness and impedance
• It encounters impairments due to different frequency
of operation
Pathloss models for In-Body
Communication
• In-Body Communication
o Deep Implant to On-Body
o Near Surface Implant to On-body
o Deep Implant to Implant
o Near Surface Implant to Implant
Implant to Body Surface
Implant to Implant
Path loss in different models of WBAN
Summary of In-Body Path Loss in
WBAN
Summary of In-Body Path Loss in
WBAN
Summary of In-Body Path Loss in
WBAN
Summary of In-Body Path Loss in
WBAN
Summary of In-Body Path Loss in
WBAN
Amplitude Attenuation in On-Body
Path Loss VS Distance for On-Body
Communication
RMS Delay at 15cm Separation
RMS Delay at 45cm Separation
Summary of On-Body Path Loss in
WBAN
Summary of On-Body Path Loss in
WBAN
Summary of On-Body Path Loss in
WBAN
Summary of On-Body Path Loss in
WBAN
OUTLINE
•
•
•
•
•
•
•
Abstract
Introduction
Summary of Architectures of WBANs
Energy Efficient MAC Protocols
MAC Frame structure
Path Loss in WBAN
Conclusion
Conclusion(1/3)
• Wireless Body Area Sensor Networks
(WBASNs)
o Emerging domain in Wireless Communication
o Most important application is Ubiquitous
Healthcare (UHC)
• Survey is done on:
o General Architectures used in WBAN for UHC
o Devices and their Functionality
o MAC protocols used in WBAN
o Advantages and Disadvantages of MAC protocols
and their tradeoffs
Conclusion(2/3)
• Path Loss in WBAN
o In-Body Communication
o On-Body Communication
o Off-Body Communication
• We conclude that
o For Static Topology in WBAN
Ta-MAC is best suited for Traffic System Architecture of
WBASN used for UHC
o For Dynamic Topology in WBAN
B-MAC is best suited for all other architectures of
WBASN
Conclusion(3/3)
• Simulation results of In-Body Communication
show that
oPath loss increases with increase in Frequency
and Distance between Sensor Nodes
oPath loss is greater for implantable sensors
than for On-Body sensors
List Of Publications
 Nadir Ali Khan, Jaffar Kulachi, Umair Rafiq, Ayesha Bibi,
Zahoor Ali Khan, Nadeem Javaid, “Ubiquitous Healthcare in
Wireless Body Area Networks”, 11th IEEE International
Conference on Ubiquitous Computing and Communications
(IUCC-2012), Liverpool, UK, 25-27 June 2012.
 Sarim Hayat, Abida Shareef, Anzar Mahmood, Zahoor Ali
Khan, Safdar Hussain Bouk, Nadeem Javaid, “Energy Efficient
MAC Protocols in Wireless Body Area Sensor Networks”, 14th
IEEE International Conference on High Performance
Computing and Communications (HPCC-2012), 25-27 June,
Liverpool, UK, 2012.

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